“It gives everybody access to solar power in a very simple way,” she says. “You don’t need to buy a share in a solar farm. You don’t need a battery. You just use the solar power that’s already being produced by others. When you’re using power in the middle of the day, you’ll be using the excess power produced by your neighbour’s rooftop solar.”

The idea for offering consumers cheaper or even free power isn’t entirely new. Several Australian power suppliers already have similar schemes that operate at certain times where there is excess renewable energy, as do many in European countries. What makes the Solar Sharer scheme unprecedented is its scale and blanket implementation, and that it is led by a national government instead of industry.

Some wonder, however, whether the new policy will work in practice or if it risks introducing perverse outcomes. For example, Dylan McConnell at the University of New South Wales says it may disincentivise new solar installations.

“You sharpen your pencil and start doing the calculations when you’re thinking about putting solar on your house,” says McConnell. “Then someone says ‘hey its free power for 3 hours in the middle of the day’, you might reconsider that decision.”

He says some people might instead buy a battery and use the free power to charge that up. Others might be upset because the expensive solar system they have just installed no longer has the same value proposition. Administering the policy will also prove complex, and the government will need to make sure that electricity suppliers don’t simply hike the price at other times to compensate for the free hours, says McConnell.

Another unknown is what would happen if there is a lengthy run of bad weather, says Alexandr Akimov at Griffith University, Gold Coast, Australia. “There is a risk,” he says, “that during rainy days, particularly when wide weather fronts cover the eastern states, that high daytime consumption combined with low solar generation could lead to spikes in daytime grid demand.”

Because Australia is so advanced in its solar journey, its policies will be widely watched by other countries. Glenn Platt at the University of Sydney says that, as other nations get deeper into their solar rollout journeys, they will “definitely” have to confront some of the same issues.

The big question, he says, is whether householders will actually change their ways as a result of the free power and move some of their energy-intensive habits like washing and drying clothes to the middle of the day. Evidence from existing free schemes in Australia is that shifting behaviours can be very difficult, especially for energy intensive heating and cooling.

The greatest potential beneficiaries of free electricity are lower-income earners, but these are also the people least likely to own the smart appliances needed to take advantage of the free power in the middle of the day.

“It means huge change, and we’re assuming that energy consumers will do certain things,” says Platt. “It’s less about the electrons and the dollars and more about the social experiment, much more about the behavioural change.”